In a large mixing bowl, combine the shredded chicken, steamed broccoli, heavy cream, cream cheese, and half of the mozzarella cheese. Mix until everything is well incorporated.
Season the mixture with garlic powder, onion powder, Italian seasoning, salt, and pepper. Stir until evenly mixed.
Transfer the chicken mixture into a greased 9x13 inch baking dish, spreading it out evenly.
Sprinkle the remaining mozzarella cheese and Parmesan cheese on top, covering the mixture completely.
Bake in the preheated oven for 25-30 minutes or until the cheese is bubbly and golden brown.
Once finished, remove the casserole from the oven and let it rest for about 5 minutes.
Before serving, garnish with chopped fresh parsley for an extra touch of flavor and color.